Yeah, we nearly always have 2nd class stamps at home, although I did also go and buy several packs twice in November in order to have enough but not too many over. We do often have to pop in to the PO for 1st class, often as a cert of posting is also required for the same item.

(I must say though, several times this year when something was unexpectedly urgent, I just stuck 2 x 2nd class on!)